Orthostatic hypotension: cardiovascular autonomic profile in the symptomatic and asymptomatic patients

Purpose: Autonomic dysfunction is an important cause of orthostatic hypotension. Patients of orthostatic hypotension may or may not be symptomatic. The study was conducted to evaluate cardiovascular autonomic status in symptomatic and asymptomatic patients of orthostatic hypotension. Methods: The study was conducted in 15 patients of orthostatic hypotension and 15 age matched subjects. On the basis of history the patients were grouped control groups symptomatic and asymptomatic. The heart rate variability was assessed from 5 min resting supine ECG. The parasympathetic and sympathetic autonomic reactivity was assessed using Ewing's battery of tests. Results: The heart rate variability and measures of autonomic reactivity were lower in the patients with orthostatic hypotension as compared to control. However, they were similar between the symptomatic and asymptomatic groups. The parasympathetic component of the heart rate variability and reactivity test was more affected in patients. The fall in the blood pressure on orthostasis was similar between the symptomatic and asymptomatic patients. Conclusion: Autonomic dysfunction is common in patients of orthostatic hypotension. The autonomic profile of symptomatic patients is not different from that of asymptomatic patients indicating that additional deficits of cerebral autoregulation may play a crucial in development of symptoms.